<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			div{
				width: 100px;
				height: 100px;
			}
			.box1{
				background: #000000;
			}
			.box2{
				/* 相对定位：相对于元素原来在文档流中的位置进行偏移 */
				background: #FF0000;
				position: relative;
				left: 100px;
				top:-50px;
			}
			.box3{
				background: #00FFFF;
			}
		</style>
	</head>
	<body>
		<div class="box1"></div>
		<div class="box2"></div>
		<div class="box3"></div>
		<div style="background: #00FF00;"></div>
	</body>
</html>
